White Tulip
. White Tulip Walter Bishop struggles with writing a letter to Peter Bishop to explain the events from 1985 that led Walter to bring Peter to his universe from the Alternate Universe. As he contemplates the final letter, he and the rest of the Fringe team are called to investigate several dead bodies in a passenger car of a train. Walter, seeing the victims' personal electronics similarly drained, suspects someone drew energy from both the people and their devices' batteries. They trace the man responsible to MIT astrophysics professor Alistair Peck, and enter his residence to search for clues, finding evidence that Alistair was studying time travel. Alistair arrives while the Fringe team is there, and activates a mechanism on his body, causing him to travel back in time. Alistair reappears on the train at the same point in time as his previous travel, again having drained the people aboard it, and alters his behavior to avoid another encounter with the Fringe team. However, when they are brought to investigate this time, they have a feeling of déjà vu and find other evidence that points to Alistair, and determine that he is trying to go back in his personal time line several months ago to prevent the death of his fiance Arlette Turling in a car collision. Alistair is found at his MIT office. Walter, having read through Alistair's writings on time travel, offers to go in and talk to Alistair first before the armed officers attempt to seize him. Walter approaches Alistair as a fellow man of science, who is replacing components that form a time machine that he has constructed within his body. Walter professes that Alistair's attempt to jump back several months would require a great deal more power than Alistair has predicted, possibly killing hundreds in the area near where he appears. Alistair, aware of this, recalls an empty field where he was at, a few blocks from where his fiancée died, and plans to use this field where only the vegetation will die out from his arrival. Walter continues to try to discourage Alistair from making the attempt by explaining his own case of coming to believe in a higher power, hoping for a sign of forgiveness in the form of a white tulip for his actions in stealing Peter from the parallel universe. With God's forgiveness, Walter believes it will be possible for Peter to forgive him once he learns the truth of who he is. Alistair considers this, but with Walter's time up, the armed forces start to move in. Alistair jumps back in time again by only a few hours to complete the modified power calculations based on Walter's comments, and to prepare a pre-addressed letter he brings with him. As his location is discovered and armed forces barge in, Alistair re-engages his time machine. Alistair's modifications have worked, as he finds himself in the field, minutes before his fiance's death. Alistair is able to make it to his fiance in time, reuniting just long enough to say "I love you" before they are both killed by the collision. In the present, the events of the episode never occurred, and Walter, having time to contemplate the letter to Peter instead of being called to the case, tosses it into the fireplace. Later, he receives an envelope in the mail—the one Alistair had prepared and instructed to be delivered to Walter on this specific date. Inside, Walter finds a hand-drawn image of a white tulip.